Sorry about my earlier misinformation. Night on a Bare Mountain was originally scored by Mussorgsky for orchestra, but Balakirev didn't like it, and Mussorgsky asked Rimsky for helped on the orchestration. After Mussorgsky died, Rimsky completed edited and re-orchestrated to piece, saving much of the original music in a rearranged format. The Rimsky version is almost always the one performed, although like many of Mussorgsky's orchestral music, the original version is coming back into fashion. I once heard Boris Godunov in the original orchestration and liked it very much, so I wonder how the original orchestration would sound. Apparently, Mussorgsky considered reworking it as a piece for piano and orchestra, that would have been interesting.